DEI Diffraction Enhance Imaging
About Diffraction Enhanced Imaging better known as DEI. DEI is a technique that is very similar to standard x-ray and can be combined with CT techniques to provide images that are far more superior to standard x-ray according to some research. 'How does DEI work?' DEI uses a synchrotron light source to create electromagnetic radiation (New medical imaging technique first to use low-dose X-rays to reveal soft tissue). A synchrotron is a cyclic type particle accelerator. The synchrotron works by synchronizing the magnetic field, electrical field, and the traveling particle beam (Synchrotron). This is done with a donut shaped ring with magnets spaced specifically inside to control the particle beam. By doing this the beam can be concentrated to focus on a specific area, the area of exposure for the image (Synchrotron Light Source). The beam that is used for DEI is similar to standard x-ray in that both beams are beams of radiation. The difference between the two beams of radiation, standard x-ray and DEI, is in how those beams are used to create the image. With standard x-ray the radiation is absorbed by dense tissue, such as bone. This creates a “negative” image. The radiation that passes through the tissue surrounding the bone exposes the film, while the radiation that is absorbed by the bone creates a negative on the film. This negative is what shows up as the image. With DEI the radiation beam uses higher energy radiation that gets diffracted by the dense bone tissue instead of absorbed. Diffraction is the deviation of a wave at the edge of an obstacle in its path (Diffraction). Unlike standard x-ray the radiation from DEI gets bounced off the dense tissue instead of absorbed, and then it passes through an analyzer crystal. It is the radiation that is bounced off the dense tissue that is used by the analyzer crystal to create the image (New medical imaging technique first to use low-dose X-rays to reveal soft tissue). 'Advantages of DEI:' Since DEI uses the diffracted radiation instead of the absorbed radiation, like that of traditional x-ray it can use higher energy level radiation to create its images. It is because of the use of higher energy radiation that passes through the tissue that it can use a lower overall dose compared to traditional x-ray. The diffraction used in DEI creates a higher quality image as well. With DEI the image shows many more details compared to standard x-ray. It is even possible to differentiate soft tissue. With a DEI image it is possible to tell the difference between bone, skin, ligaments, tendons, adipose pads, collagen, and even large blood vessels. This provides for another advantage of DEI over traditional x-ray. With DEI being able to show the differences between many types of tissue there is no need for contrast mediums. This is advantageous, because many patients do not like taking contrast mediums, and with injected mediums there is always the risk of injecting the medium improperly (New imaging technique first to use low-dose X-rays to reveal soft tissue). 'Why DEI isn’t as common as CT, MRI, and standard X-ray:' Most synchrotron light sources that are used to create DEI images are extremely large. Many synchrotrons are large enough to take up the space of entire buildings. The size of the synchrotron is necessary though. It needs the size to be able to bend the particles correctly. It is because of the synchrotron’s size that its use in DEI imaging is impractical. Also many of the more common imaging modalities have been able to improve the quality of their images. CT and MRI have had many advances in recent years and these techniques have been able to produce images that match DEI. In order to do the same thing as DEI though, multiple machines are needed, one for soft tissue, and another for dense tissue. Works Cited “New medical imaging technique first to use low-dose X-rays to reveal soft tissue”. American Association for the Advancement of Science. 08 April 2010 http://eurekalert.org/features/doe/2004-05/dnl-nmi050604.php “Synchrotron”. Wikipedia. 08 April 2010 http://en.wikipedia.org/wiki/Synchrotron “Synchrotron Light Source”. Wikipedia 08 April 2010 http://en.wikipedia.org/wiki/Synchrotron_light_source “Diffraction”. The Free Dictionary.com 08 April 2010 http://www.thefreedictionary.com/diffraction Category:Biomedical Engineering Technology